Quantitative Urine Culture in Patients with Urinary Tract Infection and Bacteremia

Abstract

A study was made of quantitative urine cultures in bacteremic patients with urinary tract infection as the only identifiable source. These patients represent the most serious form of urinary tract infection and should be recognized as significant by the criteria used for interpreting quantitative urine cultures. In 83 patients, 15 (18%) had quantitative urine counts less than 10^s colony-forming units (CFU)/mL. Ten (12%) had counts between 10⁴ and 10⁵ CFU/mL. The incidence of patients with less than 10⁴ CFU/mL (5%) is probably a low estimate because of the urine culture methods used, and this requires further study. The results of this study support the view that significant urinary infections may be associated with quantitative urine counts of less than 10⁵ CFU/mL.